Chemicals are never the way to go to buffer the ph of a tank.
I am assuming that you want to go malawi or victorian african? Tanganyika prefer even higher ph IE 8.5 to 9.5 to fully thrive.
My recommnedation.
1) Keep your proper ph you will need it later on.
2) Substrate. Change whatever you are using to a African cichlid mix, or to a coral base. This will naturally raise your ph to roughly 8.0 to 8.3.
3) Use decorations that will help with the ph. IE lace rock, tufa rock, dead coral, Shells.
4) Now that the tank has buffered naturally. You can use the proper ph when you do water changes. Basically to buffer your new tap water to the ph that won't cause your tank any harm. By the time that the proper ph wears off the corals and other things in the tank will have naturally buffered the water.
As an example. Say you tap water is testing at 6.0 and your tank is at 8.0
If you do a water change of 50% and don't buffer the new water. After the water change your tank will be at 7.0. That is far too much of a drop for the fish. It will stress them out beyond belief and you will have constant headaches (and sick fish) You would never want the ph of your tank to go up or down by more than 0.4 at any one time.
By buffering the new water. This does not become an issue. Because you are now adding water that is already at 8.2.